science of longevity

Health is a very broad and foundational element of human life which is silently interconnected with every other aspect of our life that we may hold in deep regard. Longevity i.e. the concept of extending both life span (duration of life) and health span (quality of life) has deeply intrigued me for a long time where I have tried to develop a more refreshed perspective on personal healthcare. I came across a voluminous book on longevity called ‘Outlive’ authored by Peter Attia - an engineer turned medical doctor who has a rather intriguing career profile where he made a surprising shift from being an oncology surgical resident to a McKinsey consultant working in the banking sector after which he switched back to the medical profession. The book outlines the flaws in the current healthcare system which involves medical intervention at a very late stage when it comes to treating chronic diseases (like cancer, metabolic, cardiovascular and neurological disorders) which are the leading causes of deaths among humans. Chronic diseases build through a compounding effect over a large time period which is why their effects are unnoticeable (hence appear harmless) in the early stages but materialize in a rather catastrophic manner in the later stages at which point medical intervention is extremely expensive and less effective. As we grow older, our cells naturally degrade and become less resilient compared to when we were younger thereby making it more susceptible to the harmful effects of chronic diseases. Cellular degradation is unfortunately the inevitable law of nature responsible for all the dreadful atrocities of old age ranging from muscular atrophy to declining cognition. The author urges for a paradigm shift in medical care where we first start by medically educating ourselves and then start adopting simple preventive steps very early on in our life that can eradicate the potential turmoil of the various chronic disorders that statistically plague a large population of humans in the later stages of life and consequently increase our longevity. The central idea of longevity is to counteract the natural withering force of aging to help maintain ideal cellular functionality as we move forward with time.

The science revolving around longevity is extremely fascinating. It starts with first understanding metabolism which is basically how our body utilizes diverse nutrients for our various cellular functions. A metabolically healthy body is able to efficiently transport the requisite nutrients to the various cellular locations and effectively utilize them. Metabolic disorders (like diabetes) arise due to an imbalance in the efficient and effective utilization of nutrition by cells which happens due unhealthy dietary habits. A menacing culprit in metabolic disorders is glucose (or rather excessive glucose) which is the fundamental unit of the nutrient category called carbohydrates and is the nutrient which is responsible for delivering energy to perform the necessary cellular activities within our body. The carbohydrates we consume is broken down into glucose molecules which then enters our bloodstream. The glucose molecules in our bloodstream are regulated by a molecule called insulin (which are basically chemical regulators secreted in the pancreas) which is essentially responsible for ensuring that the glucose molecules in our bloodstream are effectively transported and utilized by all the cells in our body. Once the basic energy requirements of all our cells are satiated, the excess glucose molecules get stored in various levels in our body for future usage. The primary level of storage is in the form of glycogen which serves as short-term energy storage molecules stored in the liver and muscles which can be quickly broken down into glucose molecules for energy when needed. The next level of storage resides in the form of subcutaneous fat which is actually a healthy layer of fat stored in our adipose tissues which pose no harm to the body as such and can be very usefully mobilized as an energy reserve when needed. Once the subconscious fat reserves get filled, the body still needs to store excess glucose molecules if present somewhere in the body which is where we come across visceral fat. Unlike subcutaneous fat which is a natural fat reserve earmarked for energy provision in the event of nutrient shortage without causing any adverse health effects, visceral fat is an unnatural fat reserve that gets unsystematically accumulated on various organs and muscles causing very adverse health effects on our bodily functions. Visceral fat which gets unnaturally accumulated on various organs and muscles triggers inflammatory reactions within our body and can end up tampering with the insulin receptors on the cells due to which the cells cannot receive the necessary chemical signals from the insulin molecules to regulate cellular metabolism leading to a phenomenon called insulin resistance due to which the entire glucose transportation and utilization mechanism within our body gets adversely affected. The cells in our body are thereby unable to effectively metabolize the glucose molecules in our bloodstream in order to efficiently extract energy and perform its various cellular functions which on a macroscopic level translates to very impaired bodily function. Type-II diabetes is caused by the deposition of visceral fat on the pancreas which hampers the insulin secretion. So, metabolic disorders are essentially caused by over-nourishment which ironically results in a state where humans are unable to effectively extract necessary energy or cellular building blocks from the nutritional raw material we consume to perform necessary cellular functions in our body which effectively becomes very similar to the state of being undernourished where we are unable to perform necessary cellular functions due to the absence of necessary nutritional raw material. The adversities of metabolic disorder can spill over to cardiovascular health as well where the excess visceral fat can get accumulated in our blood vessels which raises blood pressure and can cause cardiac arrests in the worst case. To properly understand cardiovascular health, we need to first delve into the nutritional categories of fats. Fats are essential nutrients that can serve as an energy source much like what carbohydrates do and also serve as building blocks for cellular components much like what proteins do. Fats are insoluble in water and hence cannot flow in the bloodstream on their own due to which they bind on special protein molecules that provide fat molecules with the necessary maneuverability to move around the body. The walls of the blood vessels which carry these fat-protein combination molecules also known as lipoproteins, are semipermeable allowing in-and-out movements across the walls to facilitate necessary molecular exchange at requisite cellular locations. A certain class of lipoproteins which are low in density and consist of a higher proportion of fats has a larger propensity to get stuck while permeating through the wall. The stuck lipoproteins get accumulated, oxidized and undergo inflammatory reactions with white blood cells following which they get calcified which effectively translate into the large lumps that clog the arteries carrying blood. Fats as mentioned earlier, are essential building blocks for biological activities and a certain class of fats called monounsaturated fats which have lower tendency to clog the arteries should be prioritized in consumption over other classes of fats which include saturated and polyunsaturated fats (primarily trans-fat) which have a higher tendency to clog the arteries thereby adversely affecting our cardiovascular health. Poor cardiovascular health can also translate adversely into neural degeneration where clogging of blood vessels that transport blood into our brain impair our brain activity as well. So, when viewed in a more microscopic lens, the various chronic disorders are highly interconnected in terms how they ultimately impair our bodily function. But even outside of chronic disorders, as mentioned earlier, aging results in cellular degradation which nevertheless ends up naturally reducing our health span as we grow older where the ailments of cellular degradation include the following: reduced organ functionality, reduced muscle strength, reduced bone density, reduced respiratory activity, reduced metabolic efficiency, reduced movement stability and reduced sleep quality.

The key to longevity i.e. reversing or at least postponing the adversities of aging and chronic disorders lie in incorporating certain systemic changes into our life. The root of chronic disorders and aging-related issues first begin with our consumption habits. From the point of view of evolution, our body is not accustomed to handling abundance in nutrient consumption which is what leads to unhealthy visceral fat accumulation in our body as food was scarce in the pre-modern times due to which our mind is biologically conditioned to respond positively towards the abundance of nutrients (especially high calorie carbohydrates and fats) even though our body responds negatively to excessive nutrient consumption as we have seen in the case of metabolic disorders. We live in a world where modern day food industries are now largely manipulating this evolutionary deficiency of ours into increased unnecessary and unhealthy food consumption through high calorie foods at the cost of our health. Processed foods which can pack together unnaturally high amounts of carbohydrates and fats unfortunately triggers positive reward signals in the brain due to the (unadjusted to the present) vestigial reward mechanisms of the past that were needed at the time in a pre-modern era of food scarcity to incentivize habits that would ensure survival and this leaves us craving for more even though we don't biologically need it for survival in a modern era of food abundance which ultimately wreaks nothing but havoc on our metabolic and cardiovascular health. Over-nourishment is thereby a prime culprit when it comes to declining health quality of humans in the modern age. Hence, the foremost step to unlocking longevity starts with calorific reduction where we consume nutrients mindfully and as per necessity much like what we did during pre-modern times (which was out of necessity in contrast) which is what our current evolutionary self is in actuality accustomed to. Calorific reduction triggers certain biological processes that are very beneficial from the point of view of unlocking longevity. In the face of abundant nutrition, our cells undergo anabolic reactions to facilitate biological processes and new cell production occurs on the back of consumed nutrients as building blocks. Calorific reduction starves our cells of fresh nutrients due to which cells switch into a more efficient state where it now undergoes catabolic reactions which unlike anabolic reactions involves breakdown of old cells to provide the necessary building blocks in place of consumed nutrients for new cell production. This entire mechanism of recycling old cells which happens as a result of calorific reduction, is called autophagy and helps increase longevity by flushing out old worn-out cells and efficiently repackaging them to build new and better functioning cells. Old worn-out cells in our body adversely affect us as it triggers inflammatory reactions within our body and hence autophagy becomes crucial in order to reverse this. Autophagy as a result of calorific reduction improves metabolic efficiency where our body is functioning more actively and better able to utilize limited energy and resources within the body. Our present-day diet has unfortunately been societally normalized around a very dominant consumption of carbohydrates while ignoring many other diverse nutrients that were regularly consumed during pre-modern times alongside carbohydrates, which is very problematic from a health standpoint. An optimal diet which is more suited to a well-functioning body is one that resembles that of pre-historic humans who lived in scarcity and consumed a small-proportioned but diverse nutritional palette of more natural i.e. less processed food. Cardiovascular exercise has the similar effect of calorific restriction in terms of triggering autophagy where the body and cells within are forced to metabolize energy more efficiently. The cellular recycling process under autophagy enhances mitochondrial efficiency and stimulates the growth of new mitochondria which are essentially energy extraction powerhouses within our cells thereby enhancing our physical stamina and ability to efficiently metabolize glucose. Cardiovascular exercise can also enhance metabolic flexibility of mitochondria along with metabolic efficiency where the mitochondria is able to efficiently metabolize both glucose and fats for energy consumption rather than only glucose as in the case of metabolically inactive and unflexible cells. Studies have also shown that cardiovascular exercise can trigger non-insulin dependent pathways for metabolizing glucose which become extremely important in the case of diabetic or insulin resistant humans. Strength exercises, on the other hand, are crucial for reversing the adverse effects of age-related muscular atrophy and reduced bone density. Strength exercises where we are effectively engaging our body muscles help stimulate muscle and bone development which is extremely crucial for maintaining sustained and optimal movement capabilities as we grow older. Alongside strength exercises, protein consumption is crucial from a dietary standpoint to help provide the necessary building blocks for sustained maintenance of muscle strength and bone density. Muscle cells like any other cell naturally degrades with age which is what causes muscular atrophy thereby leading to increasingly impaired movability as we grow older. The combination of strength exercises along with a protein-rich diet triggers a cyclic process which involves stressing i.e. wearing out of muscle cells followed by the subsequent replacement of old worn-out muscle cells with new improved muscle cells which can effectively help counteract the natural force of age-accompanied muscle cell degradation. Muscle strength along with optimal metabolic and neurobiological health play a strong role in maintaining appropriate physical stability (which concerns physical aspects like balance and posture) through efficient coordination of blood flow and nerve signals to-and-from cells, making it an extremely crucial health element, as poor body stability makes us more susceptible to chronic and in some cases irreversible injuries. Much like how modern life has transitioned into one of over-abundance of nutrition which are bodies are not evolutionarily accustomed to as compared to the pre-modern life of nutrition scarcity , humans have also transitioned into a more sedentary lifestyle i.e. a lifestyle of less movement and physical activity which again our bodies are not evolutionarily accustomed to as pre-modern life required humans to move around a lot in order to ensure survival. So, maintaining good metabolic health ultimately (and ironically) leads us to back to adopting the habits of our pre-modern ancestors i.e. restricted but diverse nourishment and regular active physical movement so as to unlock peak metabolic efficiency and activity levels. Sleep is another important element in unlocking longevity, which primarily comprises of two repeating cycles i.e. REM (Rapid Eye Movement) and NREM (Non-Rapid Eye Movement) which serve two different biological purposes. NREM sleep also termed as deep sleep where the electromagnetic waves generated by our brain (through EEG sensors) are low frequency waves signaling very low brain activity. During this phase of sleep, the brain clears out the short-term memory by transferring its information to long term memory and flushes out any neural waste from the nervous system whose accumulation is typically responsible for neural degeneration disorders. REM sleep is a phase of sleep where our brain is highly active and the electromagnetic waves generated by the brain are high frequency waves similar to the brain waves emitted when we are awake. During the REM phase, our brain is actively making various associations among different pieces of information stored in the brain and this is the sleep phase in which we encounter dreams. The REM phase of sleep is crucial for enhancing cognition and our ability to process information. Poor sleep can have very adverse effects on our metabolism and also adversely affect the necessary repair of damaged cells in our body. There is a certain elegance in how the different elements of health are strongly interconnected with one another where positive habits of diet and exercise in addition to enhancing metabolic efficiency in our bodily functions, can also deeply enhance the efficiency of neural activity in our brain in the same way that sleep does, which can thereby lead to enhanced memory capacity, cognition and information processing ability. Hence, a healthy functioning body collectively possesses good metabolic, cardiovascular and neurobiological health all of which are intricately connected creating a powerful network effect which can positively influence our emotional health as well as poor emotional health is biochemically a result of poorly regulated chemical interactions within our body which get better regulated and can come into check in a healthy functioning body. So, in summary, our habits when it comes to diet, exercise and sleep play a very important role in unlocking longevity which is an empowering insight when it comes to conquering our personal health and smartly avoiding the painful atrocities of various statistically significant health disorders that can plague us as we age. The beauty of longevity lies in the fact that while we do not have any control over our chronological age (which will always move forward in a standard manner) we have a good amount of control over our biological age which is in actuality the only age that truly matters as our biological age ultimately determines our activity levels and we possess the ability to magically slow down or maybe even reverse our biological age through simple and consistent habits through which we can lead longer and better quality lives without excess dependence on intrusive and expensive medical intervention which conventionally ends up being an unfortunate necessity during the later stages of life for the present majority of adults in the world.